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| 2. |
- Bjelosevic, Haris, et al.
(författare)
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Synthesis and structural characterisation of novel platinum-based drug candidates with extended functionality by incorporation of bis(diphenylphosphino)ferrocene units as metal chelators
- 2006
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Ingår i: Tetrahedron. - : Elsevier BV. - 0040-4020. ; 62:18, s. 4519-4527
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Tidskriftsartikel (refereegranskat)abstract
- Among the metal-based anticancer drugs, cisplatin (cis-diaminedichloroplatinum(II)) is the most widely used species in therapy. Despite its clinical success, cisplatin still suffers in generating resistance, as well as being highly toxic due to poor selectivity between healthy and sick cells. By molecular design it ought to be possible to generate new cis-platinum compounds with increased selectivity and improved cellular behaviour. In this paper, we report a synthetic pathway for construction of derivatives of 1,1'-bis(diphenylphosphino)-ferrocene, together with their corresponding cis-platinum compounds with the aim testing them for their interaction capacity with respect to various DNA models. We also report a synthetic route for a nucleoside-based cis-platinum compound containing a bidentate ferrocenylphosphine derivative connected through a succinamic-based linker to the 5-position of the heterocyclic moiety of uridine. Our preliminary kinetic investigation of 5-{N-[1-[1',2-bis(diphenylphosphino)ferrocenyl]ethyl]1-N'-[prop-2-yn-3-y l]succinamide} uridinedichloroplatinum(II) showed that this compound reacted faster with the phosphorothioate containing oligonucleotides d(T(6)p(S)T-6), with an observed first-order rate constant k(obs) = (1.4 +/- 0.1) X 10(-4) s(-1), compared with the G-N7 target in d(T(7)GGT(7)), for which the observed first-order rate constant is k(obs) = (7.2 +/- 0.5) X 10(-4) s(-1). (c) 2006 Elsevier Ltd. All rights reserved.
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| 3. |
- Bohlin, Christina, et al.
(författare)
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Product profiles in enzymic and non-enzymic oxidations of the lignin model compound erythro-1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)-1,3-propanediol
- 2005
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Ingår i: Journal of Molecular Catalysis - B Enzymatic. - : Elsevier BV. - 1381-1177 .- 1873-3158. ; 35:4-6, s. 100-107
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Tidskriftsartikel (refereegranskat)abstract
- The erythro form of the lignin model compound 1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)-1,3-propanediol (1) was oxidized with laccase/ABTS, lead(IV) tetraacetate (LTA), lignin peroxidase/H2O2, cerium(IV) ammonium nitrate (CAN) and Fenton's reagent. The product profiles obtained with the different oxidants were compared after separation, identification and quantification of the products using HPLC, UV-diode array detector and electrospray ionization mass spectrometry in positive ionization mode. The oxidants generated different product profiles that reflected their different properties. Oxidation with laccase/ABTS resulted almost exclusively in formation of 1-(3,4-dimethoxyphenyl)-3-hydroxy-2-(2-methoxyphenoxy)-1-propanone (2). Oxidation with LTA resulted in more 3,4-dimethoxybenzaldehyde (3) than ketone 2. Lignin peroxidase and CAN gave similar product profiles and aldehyde 3 was the predominant product (only small amounts of ketone 2 were formed). Oxidation with Fenton's reagent resulted in the formation of more aldehyde 3 than ketone 2 but the yields were very low. CAN served as an excellent model for the lignin peroxidase-catalyzed oxidation, while the laccase-mediator system, LTA and Fenton's reagent provided distinctly different product profiles. Erythro-1-(3,4-dimethoxyphenyl)-1,2,3-propanetriol was present among the products obtained on oxidation with LTA, lignin peroxidase, CAN and Fenton's reagent. The differences in redox potential between the oxidants afford an explanation of the diverse product patterns but other factors may also be of importance. The reactions leading to cleavage of the β-ether bond with formation of 1-(3,4-dimethoxyphenyl)-1,2,3-propanetriol (veratrylglycerol) were found to proceed without affecting the configuration at the β-carbon atom.
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| 4. |
- Dufe, Veronica T, et al.
(författare)
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A structural insight into the inhibition of human and Leishmania donovani ornithine decarboxylases by 1-amino-oxy-3-aminopropane.
- 2007
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Ingår i: Biochem J. - 1470-8728. ; 405:2, s. 261-268
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Tidskriftsartikel (refereegranskat)abstract
- The critical role of polyamines in key processes such as cell growth, differentiation and macromolecular synthesis makes the enzymes involved in their synthesis potential targets in the treatment of certain types of cancer and parasitic diseases. Here we present a study on the inhibition of human and Leishmania donovani ODC (ornithine decarboxylase), the first committed enzyme in the polyamine biosynthesis pathway, by APA (1-amino-oxy-3-aminopropane). The present study shows APA to be a potent inhibitor of both human and L. donovani ODC with a K(i) value of around 1.0 nM. We also show that L. donovani ODC binds the substrate, the co-enzyme pyridoxal 5'-phosphate and the irreversible inhibitor alpha-difluoromethylornithine (a curative agent of West African sleeping sickness) with less affinity than human ODC. We have also determined the three-dimensional structure of human ODC in complex with APA, which revealed the mode of the inhibitor binding to the enzyme. In contrast with earlier reports, the structure showed no indication of oxime formation between APA and PLP (pyridoxal 5'-phosphate). Homology modelling suggests a similar mode of binding of APA to L. donovani ODC. A comparison of the ODC-APA-PLP structure with earlier ODC structures also shows that the protease-sensitive loop (residues 158-168) undergoes a large conformational change and covers the active site of the protein. The understanding of the structural mode of APA binding may constitute the basis for the development of more specific inhibitors of L. donovani ODC.
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| 5. |
- Fernandez, Céline, et al.
(författare)
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Omics Analyses Reveal a Potential Link between Hormone-Sensitive Lipase and Polyamine Metabolism.
- 2009
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 8, s. 5008-5019
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Tidskriftsartikel (refereegranskat)abstract
- Hormone-sensitive lipase (HSL), a key enzyme in fatty acid mobilization from lipid stores, is expressed in the liver and decreased hepatic insulin sensitivity has been reported in our HSL null mouse model. Here, an integrated approach, comprising transcriptomics and proteomics together with targeted metabolite analysis, was used to investigate the liver phenotype of HSL null mice. Oligonucleotide microarray analysis revealed altered expression of genes involved in lipid and polyamine metabolism in HSL null mice compared with wild-type mice and in genes controlling the immune system in mice on high-fat diet versus mice on normal diet. Two-dimensional gel electrophoresis followed by MS and/or MS/MS allowed identification of 52 and 22 unique proteins differentially regulated according to the genotype and diet, respectively. Changes were observed mainly for proteins related to metabolism, including several proteins involved in polyamine metabolism or exhibiting methyl transferase activity. Despite the coordinated changes in mRNA and protein levels in polyamine pathways, no significant differences in levels of key polyamine metabolites were detected between the two genotypes. This study identifies a link between HSL and polyamine metabolism, which deserves further attention in view of the emerging data suggesting that disturbances in polyamine metabolism may affect insulin sensitivity. The present work also describes a limited correlation between mRNA, protein and metabolite levels, thus, underscoring the importance of integrated approaches.
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| 6. |
- Heby, Olle, et al.
(författare)
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Targeting the polyamine biosynthetic enzymes: a promising approach to therapy of African sleeping sickness, Chagas' disease, and leishmaniasis
- 2007
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Ingår i: Amino Acids. - : Springer Science and Business Media LLC. - 0939-4451 .- 1438-2199. ; 33:2, s. 359-366
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Forskningsöversikt (refereegranskat)abstract
- Trypanosomatids depend on spermidine for growth and survival. Consequently, enzymes involved in spermidine synthesis and utilization, i.e. arginase, ornithine decarboxylase (ODC), S-adenosylmethionine decarboxylase (AdoMetDC), spermidine synthase, trypanothione synthetase (TryS), and trypanothione reductase (TryR), are promising targets for drug development. The ODC inhibitor alpha-difluoromethylornithine (DFMO) is about to become a first-line drug against human late-stage gambiense sleeping sickness. Another ODC inhibitor, 3-aminooxy-1-aminopropane (APA), is considerably more effective than DFMO against Leishmania promastigotes and amastigotes multiplying in macrophages. AdoMetDC inhibitors can cure animals infected with isolates from patients with rhodesiense sleeping sickness and leishmaniasis, but have not been tested on humans. The antiparasitic effects of inhibitors of polyamine and trypanothione formation, reviewed here, emphasize the relevance of these enzymes as drug targets. By taking advantage of the differences in enzyme structure between parasite and host, it should be possible to design new drugs that can selectively kill the parasites.
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| 7. |
- Mani, Katrin, et al.
(författare)
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HIV-Tat protein transduction domain specifically attenuates growth of polyamine deprived tumor cells.
- 2007
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Ingår i: Molecular Cancer Therapeutics. - 1538-8514. ; 6:2, s. 782-788
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Tidskriftsartikel (refereegranskat)abstract
- Polyamines are essential for tumor cell growth, and the polyamine pathway represents an attractive target for cancer treatment. Several polyamine transport proteins have been cloned and characterized in bacteria and yeast cells; however, the mechanism of polyamine entry into mammalian cells remains poorly defined, although a role for proteoglycans has been suggested. Here, we show that the HIV-Tat transduction peptide, which is known to enter cells via a proteoglycan-dependent pathway, efficiently inhibits polyamine uptake. Polyamine uptake–deficient mutant cells with intact proteoglycan biosynthesis (CHO MGBG) displayed unperturbed HIV-Tat uptake activity compared with wild-type cells, supporting the notion that HIV-Tat peptide interferes with polyamine uptake via competition for proteoglycan binding sites rather than a putative downstream transporter. HIV-Tat specifically inhibited growth of human carcinoma cells made dependent on extracellular polyamines by treatment with the polyamine biosynthesis inhibitor {alpha}-difluoromethylornithine; accordingly, the Tat peptide prevented intracellular accumulation of exogenous polyamines. Moreover, combined treatment with {alpha}-difluoromethylornithine and HIV-Tat efficiently blocked tumor growth in an experimental mouse model. We conclude that HIV-Tat transduction domain and polyamines enter cells through a common pathway, which can be used to target polyamine-dependent tumor growth in the treatment of cancer.
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| 8. |
- Nasizadeh, Sima, et al.
(författare)
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Importance of polyamines in cell cycle kinetics as studied in a transgenic system.
- 2005
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Ingår i: Experimental Cell Research. - : Elsevier BV. - 1090-2422 .- 0014-4827. ; 308:May 26, s. 254-264
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Tidskriftsartikel (refereegranskat)abstract
- Polyamines are organic cations, which are considered essential for normal cell cycle progression. This view is based on results from numerous studies using a variety of enzyme inhibitors or polyamine analogues interfering with either the metabolism or the physiological functions of the polyamines. However, the presence of non-specific effects may be hard to rule out in such studies. In the present study, we have for the first time used a transgenic cell system to analyze the importance of polyamines in cell growth. We have earlier shown that expression of trypanosomal ODC in an ODC-deficient variant of CHO cells (C55.7) supported growth of these otherwise polyamine auxotrophic cells. However, one of the transgenic cell lines grew much slower than the others. As shown in the present study, the level of ODC activity was much lower in these cells, and that was reflected in a reduction of cellular polyamine levels. Analysis of cell cycle kinetics revealed that reduction of growth was correlated to prolongation of the G(1), S, and G(2) + M phases in the cells. Providing exogenous putrescine to the cells resulted in a normalization of polyamine levels as well as cell cycle kinetics indicating a causal relationship.
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| 9. |
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| 10. |
- Persson, Lo, et al.
(författare)
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Cellular polyamine homeostasis
- 2005
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Ingår i: COST 917: Biogenically active amines in food.. - 9789282839645 - 9282839648 ; 7, s. 126-126
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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